Incandescent lamp mount and method of manufacture



Oct. 27, 1959 P. B. JORDAN ETAL 2,910,611

- mcmoascsu'r LAMP MOUNT AND METHOD OF MANUFACTURE Filed Nov. 3. 1955 2 sneatmeec 1 Inv'eervtovs: PauL B. dovcian, John W. An thong,

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1959 P. 3. JORDAN s-rm. 2,910,611

INCANDESCENT LAMP MOUNT AND ME1'HOD OF MANUFACTURE Filed Nov. 3. 1955 2 Sheets-Sheet 2 Invwvtcvs: Paul, B. Jordan,

John W/Ag thonw y was ThiT' A lr t gznes.

United States Patent INCANDESCENT LAMP MOUNT AND METHOD OF MANUFACTURE Paul B. Jordan and .l'ohn W. Anthony, Cleveland Heights,

Ohio, assignors to General Electric Company, a corporation of New York Application November 3, 1955, Serial No. 544,630

6 Claims. Cl. 313-279) Our invention relates to electric incandescent lamps generally and more particularly to the filament mount or supporting structure therefor, and to methods of fabricating the mount structure.

It has been found to be highly advantageous to mount a coiled-coil filament'with its axis coincident with the axis of the lamp bulb so that during operation of the lamp, in either. a base-up or base-down position, the filament will be disposed in a vertical position whereby it exhibits improved performance, both as to efficiency and life, as compared with operation of the filament in a horizontal position. The mountstructure for supporting the filament comprises a pair of longitudinally extending lead-in wires of unequal length which are subject to distortion when exposed to vibration or shock, particularly in the heavier structures used in higher wattage lamps of about 200 or 300 watts or higher, although it is also adaptable to smaller lamps; Such distortion is prevented by employing a bridge member interconnecting the ends of the flexible lead-in wires and forming, together with the filament, a unit which is free to vibrate without relative displacement of the lead-in wiresor distortion of the filament. Such a bridge structure is disclosed and claimed in the copending application Serial No. 540,395, filed October 14, 1955, by Charles W. Pearson, and assigned to the assignee of the present invention.

It is an object of our invention to provide an improved filament mount structure of the type described above, and a method of manufacture thereof, which is particularly adaptable for use in automatic machine fabrication of the mount. To that end, we have devised a mount construction wherein the bridge-means is formed from integral continuations of the lead-in conductors in a sequence. of steps which are readily carried out on an automatic mount making machine. Our invention will be better understood by reference to the following description and the accompanying drawings, and the novel features. will be particularly pointed out in the appended-claims.

In the drawing Fig. l is a perspective view of. a lamp embodying; a mount. structure in accordance with our invention;

Figs. 2 to are perspective views showing successive steps in the fabrication of the mount;

2,910,611 Patented Oct. 27, 1959 ice several hundred millimeters. A coiled-coil tungsten filament 4 is supported from lead-in wires 5 and 6 so that its axis is coincident with the longitudinal axis 7 of the bulb =1. The said lead-in wires 5 and 6 have portions thereof sealed in a flattened press portion 8 of the stem .3 and extend outwardly to contacts on the base 9.

The elongated flexible lead-in wires 5 and 6 extend into the interior of the bulb along opposite sides of its axis 7 and have their inner ends bent to form portions 10 and 11, extending laterally toward the said axis where they are mechanically and electrically joined to the filament 4 by hook portions 12 and 13 formed therein and clamped to the filament.

In order to prevent distortion of the lead-in wires 5 and 6 and filament 4, when subjected to vibration or shock, the leads 5 and 6 are tied together by a bridge member which, in accordance with the present invention, a

is formed from integral extensions of the leads. Accordingly, the said leads 5 and 6 have portions 14 and 15 extending from the respective hooks 12 and 13 laterally away from the filament 4 in the same direction and preferably in a plane substantially normal to the plane containing the main portions of the lead wires 5 and 6. The extremities 16 and 17 ofthe respective leadl wires are then bent to extend toward each other and their spaced ends are embedded in a glass button or bead member 18. A supplementary support wire 19 has one end thereof embedded in the bead 18 and its other end coiled about a midportion of the filament 4.

It will be seen that the integral end portions 14, 16 and 15, 17 of the respective lead-in wires constitute, together with the insulating bead 18, a bridge member interconnecting the ends 16 and 11 of the respective lead wires and forming, together with the filament 4, a unit which is. free to vibrate about the point of emergence of the leadwires 5 and 6 from the stem press 8.

In Figs. 2 to 12 we have shown a preferred series of steps in the formation and assembly of the mount structure. As shown in Fig. 2, the lead-in wires 5 and 6, which are of different lengths, are first spread apart to extend angularly from the stem press 8 and are bent to then extend substantially parallel and on opposite sides of the axis 7 of the stem 3, which axis is coincident with the axis of the bulb 1.

In the next step, shown in Fig. 3, the hooks 12 and 13 are formed in the respective lea-d wires 5 and 6. The hooks are formed at equal distances back from the free tips or distal ends of the lead wires 5 and 6 and they project in the same direction and in planes normal to the plane containing both lead wires 5 and 6.

In the step shown in Fig. 4, the free ends or extremities of the lead .wires 5- and 6 are flattened and trimmed to assist their entry into the glass bead 18 in a subsequent Figs. 11 and 12 are fragmentary planviews showing L step and to assure correct spacing from each other in the finished mount. However, thisstep is not essential and may be omitted if desired.

In the next step (Fig. 5) the free ends 14 and 15 of the lead wires are bent up to form continuations of the hooks 12 and 13 and'to extend in the same direction in planes normal to the plane of the original parallel portions of the lead wires.

Inthe step illustrated in Fig. 6 the lead wires are bent at points back from (or above). the: hooks 12 and 13 to formthe portions 10 and 11 extending toward the stem axis 7 soas-to bring the respective hooks into alignment with the said axis. The free ends ;14 and 15 of the lead wires are thus also brought approxi ately. into'a plane extending through the axis 7 and normal to the -to bring their terminal end portions 16 and 17 into opposed spaced relationship approximately parallel to the stem axis, as shown in Fig. 8.

In the next step, Figs. 9 and 10, the free ends of the lead wires are gripped and spaced apart slightly (Fig. 9) while a length of glass rod or cane 18, which has been heated to a plastic condition, is brought between the opposed ends 16, 17 of the wires which are then moved toward each other to embed the flattened ends thereof into the glass rod 18 as shown in Fig. 10.,

Fig. 11 illustrates the step of inserting one end of the support wire 19 into the glass rod or bead 18 which is reheated for that purpose. The said support wire 19 is then bent to extend adjacent to the center of the filament 4 after which the free end thereof is looped around the filament as shown in Fig. 12, thereby completing the mount assembly.

Fig. 13 illustrates an alternative form of bead 18' which may be secured to the terminal portions 16 and 17 of the lead wires by holding a length of glass rod like that shown in Figs. 9 and and which has been heated to a highly plastic state, and simply forcing the plasticized rod laterally into the flattened free ends of the lead wires, followed by pressing the rod or bead between a pair of jaws to the shape shown in Fig. 13.

While we have illustrated a preferred structure and method of assembly, it will be obvious to those skilled in the art that various modifications and changes in details thereof may be made, and we aim to cover in the appended claims such modifications and changes as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric incandescent lamp comprising a sealed bulb having a longitudinal axis, a mount structure comprising a coiled-coil filament having its longitudinal axis substantially coincident with the said bulb axis, a pair of elongated flexible lead-in wires of different lengths anchored in and extending from a wall of said bulb longitudinally into the interior of the bulb and along opposite sides of its axis to the vicinity of respective ends of said filament and thence toward said bulb axis where they are electrically and mechanically joined to the said respective ends of the filament, said lead-in wires further extending laterally away from the filament in the same direction and thence toward each other with their extremities spaced apart, and an insulating member mechanically joining the said extremities of the lead-in wires forming therewith a bridge means tying the filament and the adjacent ends of the lead-in wires into a unit.

2. An electric incandescent lamp comprising a sealed bulb having a longitudinal axis, a mount structure comprising a coiled-coil filament having its longitudinal axis substantially coincident with the said bulb axis, a pair of elongated flexible lead-in wires of 'dilferent lengths anchored in and extending from a wall of said bulb longitudinally into the interior of the bulb and along opposite sides of its axis to the vicinity of respective ends of said filament and thence, toward said bulb axis where they are electrically and mechanically joined to the said respective ends of the filament, said lead-in wires further extending laterally away from the filament in the same direction and thence toward each other with their extremities spaced apart, and an insulating member mechanically joining the said extremities of the lead-in wires forming therewith a bridge means tying the filament and the adjacent ends of the lead-in wires into a unit, and a supplementary support wire secured at one end to said insulating member and embracing a midportion of the filament at its other end.

3. An electric incandescent lamp comprising a sealed bulb having a longitudinal axis, a mount structure comprising a coiled-coil filament having its longitudinal axis substantially coincident with the said bulb axis, a pair of elongated flexible lead-in wires of diiferent lengths anchored in and extending from a wall of said bulb longitudinally into the interior of the bulb and along opposite sides of its axis to the vicinity of respective ends of said filament and thence toward said bulb axis where they are electrically and mechanically joined to the said respective ends of the filament by hook portions formed in the lead-in wires and clamped upon the filament, said lead-in wires further extending laterally away from the filament in the same direction and in a plane substantially normal to the plane containing the longitudinally extending portions of the lead-in wires and thence extending toward each other with their extremities spaced apart, and an insulating member mechanically joining the said extremities of the lead-in wires forming therewith a bridge means tying the filament and the adjacent ends ofthe lead-in wires into a unit.

4. The method of mounting a filament axially of a stem having a pair of lead-in wires of difierentlength extending generally parallel from the stem and on opposite sides of its axis which comprises preliminarily forming olfset open hook portions in said wires at approximately equal distances from the distal ends of the respectie wires and then bending the wires to bring the hook portions into alignment with the stem axis, placing'a filament approximately in said stern axis with its ends within respective hook portions and clamping said hook portions to close them upon the ends of the filament, and

then bending the free ends of the Wires to extend in structure having a pair of lead-in wires of diiferent lengths extending generally parallel from a stem and on opposite sides of the axis of said stern which comprises forming ofiset open hook portions in said wires at approximately equal distances from the distal ends of the respective wires and bending the said free ends to extend from the hook portions in the same direction normal to the plane including the remaining parallel portions of the wires, then at points along said parallel portions removed from said hook portions bending the respective wires toward the said axis of the stem to bring the respective hook portions into alignment with said axis, placing a filament approximately in said axis with its ends within said hook portions and clamping said hook portions to close them upon the respective ends of the filament, bending the aforesaid free ends of the wires in directions to bring their terminal ends in opposed spaced relation approximately parallel to the said stem axis, and securing an insulating member to the spaced terminal ends of said wires to mechanically join them together.

6. The method of forming an incandescent J lamp mountstructure having a pair of lead-in wires'of different lengths extending generally parallel from a stern and on opposite sides of the axis of said stem which comprises forming ofiset open book portions in said wires at approximately equal distances from the distal ends of the respective wires and with the hook portions projecting in' the same direction and in respective planes normal to the plane containing both said wires, bending the free ends of the wires to form continuations of the hook portions and to extend in same direction normal to the said plane containing the remaining parallel portions of both said wires, then at points along said parallel portions removed from said hook portions bending the respective ,wires toward the said axis of the stem to bring the respective hook portions into alignment with'said axis, plac- 5 ing a filament approximately in said axis with its ends within said hook portions and clamping said hook portions to close them upon the respective ends of the filament, bending the aforesaid free ends of the wires in' directions to bring their terminal ends in opposed spaced relation approximately parallelto the said stem axis, and

securing an insulating member to the spaced terminal ends of said wires to mechanically join them together.

References Cited in the file of this patent UNITED STATES PATENTS Powell Mar. 8, 1927 Hull Aug. 20, 1935 Cartun May 3, 1938 Johnson Nov. 16, 1943 Coughlin Jan. 27, 1953 

